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Standard Specifications 

AND UNIFORM METHODS OF 
TESTING AND ANALYSIS FOR 

Portland Cement 




UNIVERSAL 
PORTLAND CEMENT GO. 



CHICAGO— PITTSBURG 



\a^^^jy.-^'\ o:j 



Standard Specifications 

and 

Uniform Methods of Testing and Analysis 

for 

Portland Cement 



Embracing the Report of the Committee on Standard Specifications for 

Cement of the American Society for Testing Materials; the Report of the 

Committee on Uniform Tests of Cement of the American Society 

of Civil Engineers; and the Report of the Committee on 

Uniformity in Technical Analysis for Limestones, Raw 

Mixtures and Portland Cements of the Society for 

Chemical Industry, (New York Section). 



Published by 

UNIVERSAL PORTLAND CEMENT CO. 

Chicago - - Pittsburg 

1911 






Gin 

SEP 1 Itti 



Authorized reprint from the copyrighted Proceedings of the American Society for Testing Materials. 



Standard Specifications for Portland Cement 

Adopted by the American Society for Testing Materials, 
August 16th. 1909 



GENERAL OBSERVATIONS. 

These remarks have been prepared with a view of pointing out 
the pertinent features of the various requirements and the precau- 
tions to be observed in the interpretation of the results of the tests. 

The Committee would suggest that the acceptance or rejection 
under these specifications be based on tests made by an experienced 
person having the proper means for making the tests. 

SPECIFIC GRAVITY. 

Specific gravity is useful in detecting adulteration. The results 
of tests of specific gravity are not necessarily conclusive as an indi- 
cation of the quality of a cement, but when in combination with the 
results of other tests may aftord valuable indications. 

FINENESS. 

The sieves should be kept thoroughly dry. 

TIME OF SETTING. 

Great care should be exercised to maintain the test pieces under 
as uniform conditions as possible A sudden change or wide range 
of temperature in the room in which the tests are made, a very dry 
or humid atmosphere, and other irregularities vitally affect the rate 
of setting. 

CONSTANCY OF VOLUME. 

The tests for constancy of volume are divided into two classes, 
the first normal, the second accelerated. The latter should be re- 
garded as a precautionary test only, and not infallible. So many 
conditions enter into the making and interpreting of it that it should 
be used with extreme care. 

In making the pats the greatest care should be exercised to 
avoid initial strains due to molding or to too rapid drying-out dur- 
ing the first twenty-four hours. The pats should be preserved 
under the most uniform conditions possible, and rapid changes of 
temperature should be avoided. 

The failure to meet the requirements of the accelerated tests 
need not be sufficient cause for rejection. The cement may, how- 
ever, be held for twenty-eight days, and a retest made at the end of 
that period, using a new sample. Failure to meet the requirements 

(3) 



4 Report of Special Committee on 

at this time should be considered sufficient cause for rejection, 
although in the present state of our knowledge it cannot be said 
that such failure necessarily indicates unsoundness, nor can the 
cement be considered entirely satisfactory simply because it passes 
the tests. 

SPECIFICATIONS. 
GENERAL CONDITIONS. 

All cement shall be inspected. 

Cement may be inspected either at the place of manufacture 
or on the work. 

In order to allow ample time for inspecting and testing, the 
cement should be stored in a suitable weather-tight building having 
the floor properly blocked or raised from the ground. 

The cement shall be stored in such a manner as to permit easy 
access for proper inspection and identification of each shipment. 

Every facility shall be provided by the contractor and a period 
of at least twelve days allowed for the inspection and necessary 
tests. 

Cement shall be delivered in suitable packages with the brand 
and name of manufacturer plainly marked thereon. 

A bag of cement shall contain 94 pounds of cement net. Each 
barrel of Portland cement shall contain 4 bags, and each barrel of 
natural cement shall contain 3 bags of the above net weight. 

Cement failing to meet the seven-day requirements may be held 
awaiting the results of the twenty-eight day tests before rejection. 

All tests shall be made in accordance with the methods pro- 
posed by the Committee on Uniform Tests of Cement of the Ameri- 
can Society of Civil Engineers, presented to the Society, January 
21, 1903, and amended January 20, 1904, and January 15, 1908, with 
all subsequent amendments thereto. 

The acceptance or rejection shall be based on the following re- 
quirements : 

PORTLAND CEMENT. 

Definition. — This term is applied to the finely pulverized 
product resulting from the calcination to incipient fusion of an inti- 
mate mixture of properl}^ proportioned argillaceous and calcareous 
materials, and to which no addition greater than 3% has been made 
subsequent to calcination. 

SPECIFIC GRAVITY. 

The specific gravity of cement shall not be less than 3.10. 
Should the test of cement as received fall below this requirement, a 
second test may be made upon a sample ignited at a low red heat. 
The loss in weight of. the ignited cement shall not exceed 4 per 
cent. 



Standard Specifications for Portland Cement. 5 

FINENESS. 

It shall leave by weight a residue of not more than 8% on the 
No. 100, and not more than 25% on the No. 200 sieve. 

TIME OF SETTING. 

It shall not develop initial set in less than thirty minutes; and 
must develop hard set in not less than one hour, nor more than ten 
hours. 

TENSILE STRENGTH. 

The minimum requirements for tensile strength for briquettes 
one square inch in cross section shall be as follows and the cement 
shall show no retrogression in strength within the periods specified : 

Age. Neat Cement. Strength. 

24 hours in moist air 175 lbs. 

7 days (1 day in moist air, 6 days in water) 500 lbs. 

28 days (1 day in moist air, 27 days in water) 600 lbs. 

One Part Cement, Three Parts Standard Ottawa Sand. 

7 days (1 day in moist air, 6 days in water) 200 lbs. 

28 days (1 day in moist air, 27 days in water) 275 lbs. 

CONSTANCY OF VOLUME. 

Pats of neat cement about three inches in diameter, one-half 
inch thick at the center, and tapering to a thin edge, shall be kept in 
moist air for a period of twenty-four hours. 

(a) A pat is^ then kept in air at normal temperature and ob- 
seived at intervals for at least 28 days. 

(b) Another pat is kept in water maintained as near 70° F. as 
practicable, and observed at intervals for at least 28 days. 

(c) A third pat is exposed in any convenient way in an atmos- 
phere of steam, above boiling water, in a loosely closed vessel for 
five hours. 

These pats, to satisfactorily pass the requirements, shall remain 
firm and hard and show no signs of distortion, checking, cracking, 
or disintegrating. 

SULPHURIC ACID AND MAGNESIA. 

The cement shall nc^ contain more than 1.75% of anhydrous 
sulphuric acid (SOo), nor more than 4^^^ of magnesia (MgO). 



6 Report of Special Committee on 

Report of Committee on Uniform Tests of Cement of 
the American Society of Civil Engineers. 



Presented at the Annual Meeting, January 18th, 1911. 



Your Committee on Uniform Tests of Cement presents the fol- 
lowing report: 

SAMPLING 

1. — Selection of Sample. — The selection of the sample for test- 
ing is a detail that must be left to the discretion of the engineer; 
the number and the quantity to be taken from each package will 
depend largely on the importance of the work, the number of tests 
to be made and the facilities for making them. 

2. — The sample shall be a fair average of the contents of the 
package; it is recommended that, where conditions permit, one bar- 
rel in every ten be sampled. 

3. — Samples should be passed through a sieve having twenty 
meshes per linear inch, in order to break up lumps and remove for- 
eign material ; this is also a very effective method for mixing them 
together in order to obtain an average. For determining the char- 
acteristics of a shipment of cement, the individual samples may be 
mixed and the average tested; where time will permit, however, it 
is recommended that they be tested separately. 

4. — Method of Sampling. — Cement in barrels should be sampled 
through a hole made in the center of one of the staves, midway 
between the heads, or in the head, by means of an auger or a 
sampling iron similar to that used by sugar inspectors. If in bags, 
it should be taken from surface to center. 

CHEMICAL ANALYSIS. 

5. — Significance. — Chemical analysis may render valuable 
service in the detection of adulteration of cement with considerable 
amounts of inert material, such as slag or ground limestone. It is 
of use, also, in determining whether certain constituents, believed 
to be harmful when in excess of a certain percentage, as magnesia 
and sulphuric anhydride, are present in inadmissible proportions. 

6. — The determination of the principal constituents of cement 
— silica, alumina, iron oxide and lime — is not conclusive as an in- 
dication of quality. Faulty character of cement results more fre- 
quently from imperfect preparation of the raw material or defective 
burning than from incorrect proportions of the constituents. Cement 
made from very finely-ground material, and thoroughly burned, may 
contain much more lime than the amount usually present, and still 
be perfectly sound. On the other hand, cements low in lime may, 



Uniform Tests of Cement. 7 

on account of careless preparation of the raw material, be of 
dangerous character. Further, the ash of the fuel used in burning 
may so greatly modify the composition of the product as largely 
to destroy the significance of the results of analysis. 

7. — Method. — As a method to be followed for the analysis of 
cement, that proposed by the Committee on Uniformity in the 
Analysis of Materials for the Portland Cement Industry, of the 
New York Section of the Society for Chemical Industry, and pub- 
lished in Engineering News, Vol. 50, p. 60, 1903 ; and in The En- 
gineering Record. Vol. 48, p. 49, 1903, is recommended. 

SPECIFIC GRAVITY. 

8. — SigniUcance. — The specific gravity of cement is lowered by 
adulteration and hydration, but the adulteration must be in con- 
siderable quantity to affect the results appreciably, 

9. — Inasmuch as the differences in specific gravity are usually 
very small, great care must be exercised in making the determina- 
tion. 

10. — Apparatus and Method. — The determination of specific 
gravity is most conveniently made with Le Chatelier's apparatus. 
This consists of a flask (-D), Fig. 1, of 120 cu. cm. (7.32 cu. in.) 
capacity, the neck of which is about 20 cm. (7.87 in.) long; in the 
middle of this neck is a bulb (C), above and below which are two 
marks (F) and {E) ; the volume between these marks is 20 cu. cm. 
(1.22 cu. in.). The neck has a diameter of about 9 mm. (0.35 
in.), and is graduated into tenths of cubic centimeters above the 
mark {F). 

11. — Benzine (62° Baume naphtha), or kerosene free from 
water, should be u^ed in making the determination. 

12. — The specific gravity is determined as follows : 

The flask is filled with either of these liquids to the lower mark 
(£), and 64 g. (2.25 oz.) of powder, cooled to the temperature of 
the liquid, is gradually introduced through the funnel {B) [the 
stem of which extends into the flask at the top of the bulb (C)], 
until all the powder is introduced, and the level of the liquid rises 
to some division of the graduated neck. This reading plus 20 cu. 
cm. is the volume displaced by 64 g. of the powder. 

13. — The specific gravity is then obtained from the formula: 

.- ^ . Weight of Cement, in grammes. 

Specific Gravity ^^^^ — -. , ^^ , -. r^^ -. 

Displaced Volume, m cubic centimeters. 

14. — The flask, during the operation, is kept immersed in water 
in a jar {A), in order to avoid variations in the temperature of the 
liquid. The results should agree within 0.01. The determination 
of specific gravity should be made on the cement as ireceived ; and, 
should it fall below 3.10, a second determination should be made 
on the sample ignited at a low red heat. 

15. — A convenient method for cleaning the apparatus is as 
follows : The flask is inverted over a large vessel, preferably a glass 



8 



Report of Special Committee o^ 



jar, and shaken vertically until the liquid starts to flow freely; it 
is then held still in a vertical position until empty; the remaining 
traces of cement can be removed in a similar manner by pouring 
into the flask a small quantity of clean liquid benzine or kerosene 
and repeating the operation. 

B 




lechateliers specific gravity apparatus. 
Fig. 1. 



FINENESS. 

16. — Significance. — It is generally accepted that the coarser 
particles in cement are practically inert, and it is only the ex- 
tremely fine powder that possesses adhesive or cementing qualities. 
The more finely cement is pulverized, all other conditions being 
the same, the more sand it will carry and produce a mortar of a 
given strength. 

17. — The degree of final pulverization which the cement re- 
ceives at the place of manufacture is ascertained by measuring the 
residue retained on certain sieves. Those known as the No. 100 
and No. 200 sieves are recommended for this purpose 



Uniform Tests of Cement. 9 

18. — Apparatus. — The sieves should be circular, about 20 cm. 
(7.87 in.) in diameter, 6 cm. (2.36 in.) high, and provided with a 
pan, 5 cm. (1.97 in.) deep, and a cover. 

19. — The wire cloth should be of brass wire having the follow- 
ing diameters : 

No. 100, 0.0045 in. ; No. 200, 0.0024 in. 

20. — This cloth should be mounted on the frames without dis- 
tortion; the mesh should be regular in spacing and be within the 
following limits : 

No. 100, 96 to 100 meshes to the linear inch. 
No. 200, 188 to 200 meshes to the linear inch. 

21. — Fifty grammes (1.76 oz.) or 100 g. (3.52 oz.) should be 
used for the test, and dried at a temperature of 100"^ cent. (212° 
Fahr.) prior to sieving. 

22. — Method. — The thoroughly dried and coarsely screened 
sample is weighed and placed on the No. 200 sieve, which, with pan 
and cover attached, is held in one hand in a slightly inclined posi- 
tion, and moved forward and backward, at the same time striking 
the side gently with the palm of the other hand, at the rate of about 
200 strokes per minute. The operation is continued until not more 
than one-tenth of 1% passes through after one minute of continu- 
ous sieving. The residue is weighed, then placed on the No. 100 
sieve and the operation repeated. The work may be expedited by 
placing in the sieve a small quantity of large steel shot. The results 
should be reported to the nearest tenth of 1 per cent. 

NORMAL CONSISTENCY. 

23. — Significance. — The use of a proper percentage of water in 
making the pastes* from which pats, tests of setting, and briquettes 
are made, is exceedingly important, and affects vitally the results 
obtained. 

24. — The determination consists in measuring the amount of 
water required to reduce the cement to a given state of plasticity, 
or to what is usually designated the normal consistency. 

25. — The Committee recommends the following method for 
determining normal consistency. 

26. — Method. Vicat Needle Apparatus. — This consists of a 
frame {K), Fig. 2, bearing a movable rod (L), with the cap {A) at 
one end, and at the other the cylinder (B), 1 cm. (0.39 in.) in diam- 
eter, the cap, rod, and cylinder weighing- 300 g. (10.58 oz.). The 
rod, which can be held in any desired position by a screw (F), carries 
an indicator, which moves over a scale (graduated to centimeters) 
attached to the frame (K). The paste is held by a conical, hard- 

*The term "paste" is used in this report to designate a mixture of cement 
and water, and the word "mortar" a mixture of cement, sand and water. 



10 



Report of Special Committee on 



rubber ring (/), 7 cm. (276 in.) in diameter at the base, 4 cm. 
(1.57 in.) high, resting on a glass plate (/), about 10 cm. (3.94 in.) 
square. 

27. — In making the determination, the same quantity of cement 
as will be subsequently used for each batch in making the briquettes., 
but not less than 500 g., is kneaded into a paste, as described in 
Paragraph 52, and quickly formed into a ball with the hands, com- 
pleting the operation by tossing it six times from one hand to the 
other, maintained 6 in. apart ; the ball is then pressed into the rubber 
ring, through the larger opening, smoothed off, and placed (on its 
large end) on a glass plate and the smaller end smoothed off with 




YICAT NEEDLE. 

Fig. 2. 



a trowel ; the paste, confined in the ring, resting on the plate, is 
placed under the rod bearing the cylinder, which is brought in con- 
tact with the surface and quickly released. 

28. — The paste is of normal consistency when the cylinder in 
one minute from the time it is released penetrates to a point in the 
mass 10 mm. (0.39 in.) below the top of the ring. Great care must 
be taken to fill the ring exactly to the top. The apparatus must be 
free from all vibrations during the test. 

29. — The trial pastes are made with varying percentages of 
water until the correct consistency is obtained. 

30. — The Committee has recommended, as normal, a paste, the 
consistency of which is rather wet, because it believes that variations 



Uniform Tests of Cement. 



11 



in the amount of compression to which the briquette is subjected in 
moulding are Hkely to be less with such a paste. 

31. — Having determined in this manner the proper percentage 
of water required to produce a paste of normal consistency, the 
proper percentage required for the mortars is obtained from the 
table below. 

Percentage of Water for Standard Mortars. 





One cement, 




One cement, 




One cement, 


Neat. 


three standard 


Neat. 


three standard 


Neat. 


three standard 




Ottawa sand. 




Ottawa sand. 




Ottawa sand. 


15 


8.0 


23 


9.3 


31 


10.7 


16 


8.2 


24 


9.5 


32 


10.8 


17 


8.3 


25 


9.7 


33 


11.0 


18 


• 8.5 


26 


9.8 


34 


11.2 


19 


8.7 


27 


10.0 


35 


11.5 


20 


8.8 


28 


10.2 


36 


11.5 


21 


9.0 


29 


10.3 


37 


11.7 


22 


9.2 


30 


10.5 


38 


11.8 



TIME OF SETTING. 

32. — Significance. — The object of this test is to determine the 
time which elapses from the moment water is added until the paste 
ceases to be fluid and plastic (called the ''initial set"), and also the 
time required for it to acquire a certain degree of hardness (called 
the "final" or ''hard set"). The former of these is the more im- 
portant, since, with the commencement of setting, the process of 
crystallization or hardening is said to begin. As a disturbance of 
this process may produce a loss of strength, it is desirable to com- 
plete the operation of mixing and moulding or incorporating the 
mortar into the work before the cement begins to set. 

33. — It is usual to measure arbitrarily the beginning and end of 
the setting by the penetration of weighted wires of given diameters. 

34. — Method. — For this purpose the Vicat Needle, which has 
already been described in Paragraph 26, should be used. 

35. — In making the test, a paste of normal consistency is 
moulded and placed under the rod (L), Fig. 2, as described in Para- 
graph 27; this rod, bearing the cap (D) at one end and the needle 
(H), 1 mm. (0.039 in.) in diameter, at the other, weighing 300 g. 
(10.58 oz.). The needle is then carefully brought in contact with 
Ihe surface of the paste and quickly released. 

36. — The setting is said to have commenced when the needle 
ceases to pass a point 5 mm. (0.20 in.) above the upper surface of 
the glass plate, and is said to have terminated the moment the needle 
does not sink visibly into the mass. 

37. — The test pieces should be stored in moist air during the 
test ; this is accomplished by placing them on a rack over water con- 
tained in a pan and covered with a damp cloth, the cloth to be kept 
away from them by means of a wire screen ; or they may be stored 
m a moist box or closet. 



12 Report of Special Committee on 

38. — Care should be taken to keep the needle clean, as the collec- 
tion of cement on the sides of the needle retards the penetration, while 
cement on the point reduces the area and tends to increase the 
penetration. 

39. — The determination of the time of setting is only approxi- 
imate, being materially affected by the temperature of the mixing 
water, the temperature and humidity of the air during the test, the 
percentage of water used, and the amount of kneading the paste 
receives. 

STANDARD SAND. 

40. — The Committee recommends the natural sand from Ottawa, 
111., screened to pass a sieve having 20 meshes per linear inch and 
retained on a sieve having 30 meshes per linear inch ; the wires to 
have diameters of 0.0165 and 0.0112 in., respectively, i. e., half the 
width of the opening in each case. Sand having passed the No. 20 
sieve shall be considered standard when not more than l^'' passes a 
No. 30 sieve after one minute's continuous sifting of a 500-g. 
sample*. 

FORM OF TEST PIECES. 

41. — For tension tests the Committee recommends the form of 
test piece shown in Fig. 3. 

42. — For compression tests a 2-in. cube is recommended. 

MOULDS. 

43. — The moulds should be made of brass, bronze, or some 
equally non-corrodible material, having sufficient metal in the sides 
to prevent spreading during moulding. 

44. — Gang moulds, which permit moulding a number of bri- 
quettes at one time, are preferred by many to single moulds ; since 
the greater quantity of mortar that can be mixed tends to produce 
greater uniformity in the results. The type shown in Fig. 4 is 
recommended. 

45. — The moulds should be wiped with an oily cloth before 
using. 



♦This sand may be obtained from tlip Ottawa Silica Company at a cost of 
two cents per pound, f. o. b. cars, Ottawa, Illinois. 



Uniform Tests of Cement. 



13 




DETAILS FQR. BRIQUETTE. 

Pig. 3. 




DETAILS FOR GANG MOULD. 



/ 



-m 



14 Report of Special Committee on 

MIXING. 

46. — All proportions should be stated by weight ; the quantity of 
water to be used should be stated as a percentage of the dry material. 

47. — The metric system is recommended because of the con- 
venient irelation of the gramme and the cubic centimeter. 

48. — The temperature of the room and the mixing water should 
be as near 21° cent. (70° Fahr.) as it is practicable to maintain it. 

49. — The sand and cement should be thoroughly mixed dry. 
The mixing should be done on some non-absorbing surface, prefer- 
ably plate glass. If the mixing must be done on an absorbing sur- 
face it should be thoroughly dampened prior to use. 

50. — The quantity of material to be mixed at one time depends 
on the number of test pieces to be made; about 1,000 g. (35.28 oz.) 
makes a convenient quantity to mix, especially by hand methods. 

51. — The Committee, after investigation of the various mechan- 
ical mixing machines, has decided not to recommend any machine 
that has thus far been devised, for the following reasons : 

( 1 ) The tendency of most cement is to "ball up" in the machine, 
thereby preventing the working of it into a homogeneous paste; (2) 
there is no means of ascertaining when the mixing is complete with- 
out stopping the machine, and (3) the difficulty of keeping the ma- 
chine clean. 

52. — Method. — The material is weighed and placed on the mix- 
ing table, and a crater formed in the center, into which the proper 
percentage of clean water is poured ; the material on the outer edge 
is turned into the crater by the aid of a trowel. As soon as the 
water has been absorbed, which should not require more than one 
minute, the operation is completed by vigorously kneading with the 
hands for an additional one minute, the process being similar to that 
used in kneading dough. A sand-glass affords a convenient guide 
for the time of kneading. During the operation of mixing, the 
hands should be protected by gloves, preferably of rubber. 



MOULDING. 

53. — Having worked the paste or mortar to the proper consist- 
ency, it is at once placed in the moulds by hand. 

54. — The Committee has been unable to secure satisfactory re- 
sults with the present moulding machines ; the operation of machine 
moulding is very slow, and the present types permit of moulding 
but one briquette at a time, and are not practicable with the pastes 
or mortars herein recommended. 



Uniform Tests of Cement. 15 

55. — Method. — The moulds should be filled immediately after 
the mixing is completed, the material pressed in firmly with the 
fingers and smoothed ofif with a trowel without mechanical ramming ; 
the material should be heaped up on the upper surface of the mould, 
and, in smoothing off, the trowel should be drawn over the mould 
in . such a manner as to exert a moderate pressure on the excess 
material. The mould should be turned over and the operation re- 
peated. 

56.— A check upon the uniformity of the mixing and moulding 
is afforded by weighing the briquettes just prior to immersion, or 
upon removal from the moist closet. Briquettes which vary in 
weight more than 3% from the average should not be tested. 



STORAGE OF THE TEST PIECES. 

57. — During the first 24 hours after moulding, the test pieces 
should be kept in moist air to prevent them from drying out. 

58. — A moist closet or chamber is so easily devised that the use 
of the damp cloth should be abandoned. Covering the test pieces 
with a damp cloth is objectionable, as commonly used, because the 
cloth may dry out unequally, and, in consequence, the test pieces are 
not all maintained under the same condition. Where a moist closet 
is not available, a cloth may be used and kept uniformly wet by 
immersing the ends in water. It should be kept from direct contact 
with the test pieces by means of a wire screen or some similar ar- 
langement. 

59. — A moist closet consists of a soapstone or slate box, or a 
metal-lined wooden box — the metal lining being covered with felt and 
this felt kept wet. The bottom of the box is so constructed as to 
hold water, and the sides are provided with cleats for holding glass 
shelves on which to place the briquettes. Care should be taken to 
keep the air in the closet uniformly moist. 

60. — After 24 hours in moist air, the test pieces for longer 
periods of time should be immersed in water maintained as near 
21° cent. (70° Fahr.) as practicable; they may be stored in tanks or 
pans, which should be of non-corrodible material. 



TENSILE STRENGTH. 

61. — The tests may be made on any machine. A solid metal 
clip, as shown in Fig. 5, is recommended. This clip is to be used 
without cushioning at the points of contact with the test specimen. 
The bearing at each point of contact should be }i in. wide, and the 
distance between the center of contact on the same clip should be 
1% in. 



16 



Report of Special Committee on 



62. — Test pieces should be broken as soon as they are removed 
from the water. Care should be observed in centering the briquettes 
in the testing machine, as cross-strains, produced by improper center- 
ing, tend to lower the breaking strength. The load should not be 
applied too suddenly, as it may produce vibration, the shock from 
which often breaks the briquettes before the ultimate strength is 
reached. Care must be taken that the clips and the sides of the 
briquette be clean and free from grains of sand or dirt, which would 
prevent a good bearing. The load should be applied at the rate of 
600 lb. per min. The average of the briquettes of each sample 
tested should be taken as the test, excluding any results which are 
manifestly faulty. 




FORM OF CLIP. 



Fig. 5. 



Uniform Tests of Cement. 17 

CONSTANCY OF VOLUME. 

63. — Significance. — The object is to develop those qualities 
which tend to destroy the strength and durability of a cement. As 
it is highly essential to determine such qualities at once, tests of this 
character are for the most part made in a very short time, and are 
known, therefore, as accelerated tests. Failure is revealed by crack- 
ing, checking, swelling, or disintegration, or all of these phenomena. 
A cement which remains perfectly sound is said to be of constant 
volume. 

64. — Methods. — Tests for constancy of volume are divided into 
two classes : ( 1 ) normal tests, or those made in either air or water 
maintained at about 21° cent. (70° Fahr.), and (2) accelerated tests, 
or those made in air, steam, or water at a temperature of 45° cent. 
(113° Fahr.) and upward. The test pieces should be allowed to 
remain 24 hours in moist air before immersion in water or steam, 
or preservation in air. 

65. — For these tests, pats, about 7^ cm. (2.95 in. in diameter, 
1% cm. (0.49 in.) thick at the center, and tapering to a thin edge, 



18 



Report of Special Committee on 



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Uniform Tests of Cement. 19 

should be made, upon a clean glass plate [about 10 cm. (3.94 in.) 
square], from cement paste of normal consistency. 

66. — Normal Test. — A pat is immersed in water maintained as 
near 21° cent. (70° Fahr.) as possible for 28 days, and observed at 
intervals. A similar pat, after 24 hours in moist air, is maintained 
in air at ordinary temperature and observed at intervals. 

67. — Accelerated Test. — A pat is placed in an atmosphere of 
steam upon a wire screen 1 in. above boiling water for five (5) 
hours. The apparatus should be so constructed as to permit the 
free escape of steam and maintain atmospheric pressure. Since the 
type of apparatus used has a great influence on the uniformity of the 
results, that shown in Fig. 8 is recommended. 

68. — To pass these tests satisfactorily, the pats should remain 
firm and hard, and show no signs of cracking, distortion or disinte- 
gration. 

69. — Should the pat leave the plate, distortion may be detected 
best with a straight-edge appHed to the surface which was in contact 
with the plate. 

70. — In the present state of our knowledge it cannot be said 
that cement should necessarily be condemned simply for failure to 
pass the accelerated tests; nor can a cement be considered entirely 
satisfactory simply because it has passed these tests. 

Submitted on behalf of the Committee, 

George S. Webster, 

Chairman. 

Richard L. Humphrey, 
Secretary. 



January 18th, 1911. 



Committee. 
George S. Webster, 
Richard L. Humphrey, 
George F. Swain, 
Alfred Noble, 
Louis C. Sabin, 
S. B. Newberry, 
Clifford Richardson, 
W. B. W. Howe, 
F. H. Lewis. 



20 Report of Committee on 

Reprint of Report Authorized by the Society. 



New York Section Society for Chemical Industry 



Method Suggestep for the Analysis of Limestones, Raw Mix- 
tures AND Portland Cements by the Committee on 
Uniformity in Technical Analysis with the 
Advice of W. F. Hillebrand. 

SOLUTION. 

One-half gram of the finely-powdered substance is to be 
weighed out and, if a limestone or unburned mixture, strongly ig- 
nited in a covered platinum crucible over a strong blast for fifteen 
minutes, or longer if the blast is not powerful enough to effect com- 
plete conversion to a cement in this time. It is then transferred to 
an evaporating dish, preferably a platinum for the sake of celerity 
in evaporation, moistened with enough water to prevent lumping, 
and 5 to 10 c. c. of strong HCl added and digested with the aid of 
gentle heat and agitation until solution is complete. Solution may 
be aided by Hght pressure with the flattened end of a glass rod."*" 
The solution is then evaporated to dryness, as far as this may be 
possible on the bath. 

SILICA (SiO^). 

The residue without further heating is treated at first with 5 to 
10 c. c. of strong HCl, which is then diluted to half strength or less, 
or upon the residue may be poured at once a larger volume of acid 
of half strength. The dish is then covered and digestion allowed to 
go on for 10 minutes on the bath, after which the solution is filtered 
and the separated silica washed thoroughly with water. The filtrate 
is again evaporated to dryness, the residue without further heating, 
taken up with acid and water and the small amount of silica it con- 
tains separated on another filter paper. The papers containing the 
residue are transferred wet to a weighed platinum crucible, dried, 
ignited, first over a Bunsen burner until the carbon of the filter is 
completely consumed, and finally over the blast for 15 minutes and 
checked by a further blasting for 10 minutes or to constant weight. 

*lf anything remains undecomposed it should he separated, fused with a lit- 
tle Na2C03, dissolved and added to the original solution. Of course a small 
amount of separated non-gelatinous silica is not to be mistaken for undecom- 
posed matter. 



Uniformity in Technical Analysis. 21 

The silica, if great accuracy is desired, is treated in the crucible with 
about 10 c. c. of HFl and four drops of HoSO^ and evaporated over 
a loAv flame to complete dryness. The small residue is finally blasted, 
for a minute or two, cooled and weighed. The difference between 
this weight and the weight previously obtained gives the amount 
of silica."^ 



ALUMINA AND IRON (Al^O.^ AND Fe.Og). 

The filtrate, about 250 c. c, from the second evaporation for 
SiOg, is made alkaline with NH^OH after adding HCl, if need be, 
to insure a total of 10 to 15 c. c. strong acid, and boiled to expel 
excess of NH,, or until there is but a faint odor of it, and the pre- 
cipitate iron and aluminum hydrates, after settling, are washed once 
by decantation and slightly on the filter. Setting aside the filtrate, 
the precipitate is dissolved in hot dilute HCl, the solution passing 
into the beaker in which the precipitation was made. The aluminum 
and iron are then reprecipitated by NH_^OH, boiled and the second 
precipitate collected and washed on the same filter used in the first 
instance. The filter paper, with the precipitate, is then placed in a 
weighed platinum crucible, the paper burned off and the precipitate 
ignited and finally blasted 5 minutes, with care to prevent reduction, 
cooled and weighed as ALOg+FeoOg.''' 



IRON (Fe^Og). 

The combined iron and aluminum oxides are fused in a plati- 
num crucible at a very low temperature with about 3 to 4 grams of 
KHSO4, or, better, NaHS04, the melt taken up with so much dilute 
H2SO4 that there shall be no less than 5 grams absolute acid and 
enough water to effect solution on heating. The solution is then 
evaporated and eventually heated till acid fumes come off copiously. 
After cooling and redissolving in water the small amount of silica is 
filtered out, weighed and corrected by HFl and H2SO4.* The filtrate 
is reduced by zinc, or preferably by hydrogen sulphide, boiling out 
the excess of the latter afterwards while passing CO2 through the 
flask, and titrated with permanganate. § The strength of the per- 
manganate solution should not be greater than .0040 gr. FeoOg 
per c. c. 



*For ordinary control in the plant laboratory this correction may, perhaps, 
be neglected; the double evaporation never. 

tThis precipitate contains TiOa, PcOn, MngOi. 

JThis correction of AI2O3 FeaOs for silica should not be made when the HFl 
correction of the main silica has been omitted, unless thai silica was obtained by 
only one evaporation and filtration. After two evaporations and filtrations 1 to 2 
mg. of SiO are still to be found with the AI0O3 FeoQs. 

§In this way only is the influence of titanium to be avoided and a correct 
result obtained for iron. 



22 Report of Committee on 



LIME (CaO). 

To the combined filtrate from the AlsOg-f-FCgO^ piecipitate a 
few drops of NH^OH are added, and the solution brought to boil- 
ing. To the boiling solution 20 c. c. of a saturated solution of 
ammonium oxalate are added, and the boiling continued until the 
precipitated CaCaO^ assumes a well-defined granular form. It is 
then allowed to stand for 20 minutes, or until the precipitate has 
settled, and then filtered and washed. The precipitate and filter are 
placed wet in a platinum crucible, and the paper burned off over a 
small flame of a Bunsen burner. It is then ignited, redissolved in 
HCl, and the solution made up to 100 c c. with water. Ammonia 
is added in slight excess, and the liquid is boiled. If a small amount 
of A]203 separates, this is filtered out, weighed, and the amount 
added to that found in the first determination, when greater accu- 
racy is desired. The lime is then reprecipitated by ammonium oxal- 
ate, allowed to stand until settled, filtered, and washed,''' weighed as 
oxide by ignition and blasted in a covered crucible to constant 
weight, or determined with dilute standard permanganate. *■ 



MAGNESIA (MgO). 

The combined filtrates from the calcium precipitates are acidi- 
fied with HCl and concentrated on the steam bath to about 150 c. c, 
10 c. c. of saturated solution of Na(NH4)HP04 are added, and the 
solution boiled for several minutes. It is then removed from the 
flame and cooled by placing the beaker in ice water. After cooling, 
NH4OH is added drop by drop with constant stirring until the crys- 
talline ammonium-magnesium ortho-phosphate begins to form, and 
then in moderate excess, the stirring being continued for several 
minutes. It is then set aside for several hours in a cool atmosphere 
and filtered. The precipitate is redissolved in hot dilute HCl, the 
solution made up to about 100 c. c, 1 c. c. of a saturated solution of 
Na(NH4)HP04 added, and ammonia drop by drop, with constant 
stirring until the precipitate is again formed as described and the 
ammonia is in moderate excess. It is then allowed to stand for 
about 2i hours, when it is filtered on a paper or a Gooch crucible, 
ignited, cooled and weighed as MgoPsO^. 



ALKALIES (K,0 and Na,0). 

For the determination of the alkalies, the well-known method 
of Prof. J. Lawrence Smitli is to be followed, either with or without 
the addition of CaCO, with NH.Cl. 



*The volume of wash-wator should not be too large ; vide Hillebrand. 

fThe accuracy of this mcMliod adinits of criticism, l)ut its convenience . and 
rapidity demand its insertion. 



Uniformity in Technical Analysis. 23 

ANHYDROUS SULPHURIC ACID (SO,). 

One gram of the substance is dissolved in 15 c. c. of HCl, 
filtered and residue washed thoroughly.'^ 

The solution is made up to 250 c. c. in a beaker and boiled. To 
the boiling solution 10 c. c. of a saturated solution of BaCL is added 
slowly drop by drop from a pipette and the boiling continued until 
the precipitate is well formed, or digestion on the steam bath may 
be substituted for the boiling. It is then set aside over night, or for 
a few hours, filtered, ignited and weighed as BaSO^. 

TOTAL SULPHUR. 

One gram of the material is weighed out in a large platinum 
crucible and fused with Na^CO.. and a little KNOg, being careful to 
avoid contamination from sulphur in the gases from source of heat. 
This may be done by fitting the crucible in a hole in an asbestos 
board. The melt is treated in the crucible with boiling water and 
the liquid poured into a tall narrow beaker and more hot water 
added until the mass is disintegrated. The solution is then filtered. 
The filtrate contained in a No. 4 beaker is to be acidulated with 
HCl and made up to 250 c. c. with distilled water, boiled, the sul- 
phur precipitated as BaSO^ and aJlowed to stand over night or for 
a few hours. 

LOSS ON IGNITION. 

Half a gram of cement is to be weighed out in a platinum 
crucible, placed in a hole in an asbestos board so that about -/s of 
the crucible projects below, and blasted 15 minutes, preferably w^ith 
an inclined flame. The loss by weight, which is checked by a second 
blasting of 5 minutes, is the loss on ignition. 

Alay, 1903 : Recent investigations have shown that large errors 
in result's are> often due to the use of impure distilled water and 
reagents. The analyst should, therefore, test his distilled water by 
evaporation and his reagents by appropriate tests before proceeding 
with his work. 



*Evaporation to dryness is unnecessary, unless gelatinous silica should have 
separated and should never be performed on a bath heated by gas ; vide Hille- 
brand. 




iM 



Sales of nearly one-half 
million barrels of Universal 
Portland Cement to one 
railroad in a single year m- 
dicate the satisfaction which 
Universal gives the engin- 
eers of this road m their 
extensive and varied im- 
provements involving every 
type of plain and reinforced 
concrete construction. 

Universal Portland Cement Co. 

Chicago— Pittsburg 
Annual Output 10,000,000 Barrels 



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